This invention relates to a negative mask unit which permits photoprinting both from new-type negative films that are handled housed in cartridges and from conventional negative films such as 135 films.
New-type films are now available which are fed from a cartridge for development and photoprinting, and fed back into the original cartridge for storage. Compared with conventional film, such new-type film is compact, easy to handle, and suited for automation of development and printing. Also, developed and printed film can be stored in the original cartridge.
While new-type negative film has such desirable properties, it is impossible to use a conventional photoprinter for exposure of such new-type film because it has a different width from any of conventional films such as 135 and 110 type negative films, and thus, its frames are not aligned with the exposure window of the negative mask provided at the exposure position in a conventional photoprinter.
New-type negative film has a magnetic information portion in the form of a transparent magnetic body for recording shooting conditions and other information. Thus, a photoprinter for processing such new-type negative film must have a reading means for reading such magnetic information.
For the above reasons, as photoprinters for processing new-type negative film, turntable-type printers have been proposed in which a cartridge is fed to a scanner unit or a printing/exposure unit and the negative film is unwound from the cartridge for printing/exposure, as disclosed in Japanese patent publication 7-36120. These devices can process only new-type negative film. In these devices, a negative mask unit including a negative mask at the exposure position can process only new-type negative film.
Since new-type film was introduced into the market only recently, such film is not used so much by ordinary people. Size 135 film is still the mainstream in the photographic industry. But with the increasing number of cameras for new-type film, it is expected that the workload of printing from new-type film will increase.
On the other hand, many people will keep using conventional size 135 film. Thus, photo studios will have to keep two photoprocessing machines, one for conventional film and the other for new-type film. Purchasing two such machines will be a heavy burden economically for photo shop owners.
Thus, in many photo shops, in order to process new-type film, they replace main components of a conventional photoprinter such as the negative mask and film guide with those for new-type film, instead of purchasing a new machine for new-type film. Of course, purchasing such replacement parts is a much more economical solution than purchasing a new processing machine. But these parts have to be exchanged every time the film type is changed, so that the work efficiency tends to markedly worsen.
In some photo shops, in order to minimize the frequency of replacements, only when a predetermined number of size new-type films have been collected will they be processed. This is possible because new-type film orders are still much fewer in number than size 135 orders. But since new-type film orders are expected to increase in the near future, an improved negative mask unit which is easy to exchange is desired.
An object of this invention is to provide a negative mask unit which can perform exposure processing from either of reference film and new-type film simply by exchanging a negative mask in the negative mask unit for reference film or new-type film and selecting the direction of insertion of negative film, and which is simple in structure, low in cost, and can process printing/exposure with extremely high efficiency.